Most of the birds which have left Britain have followed the traditional route via Italy, though two at least have headed south-west on the recently discovered second route through Spain. These 14 cuckoos had cleared the English Channel by 7th July, but three birds known to be still in Britain are from those tagged in Scotland at the most northerly site used on the scheme. The final bird out of the 18 currently being tracked - named Karma - has disappeared with no updates coming from its tag.
Another bird - named Whortle - has travelled over 1,000 km (620 miles) in about 48 hours to get to its current location in France, while other individuals are in Germany and Corsica. One, which remains in Britain, still needs to be named by a generous sponsor.
The latest position of each of the tagged Common Cuckoos - an interactive map is available on the BTO Cuckoos page.
To follow each Cuckoo's progress, the BTO has an ongoing multi-blog for each bird, continuously updated as data from the tags comes in. Visit www.bto.org/cuckoos for more details.